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https://www.readbyqxmd.com/read/28324615/construction-of-low-ethanol-wine-yeasts-through-partial-deletion-of-the-saccharomyces-cerevisiae-pdc2-gene
#1
Raúl Andrés Cuello, Karina Johana Flores Montero, Laura Analía Mercado, Mariana Combina, Iván Francisco Ciklic
We propose an alternative GMO based strategy to obtain Saccharomyces cerevisiae mutant strains with a slight reduction in their ability to produce ethanol, but with a moderate impact on the yeast metabolism. Through homologous recombination, two truncated Pdc2p proteins Pdc2pΔ344 and Pdc2pΔ519 were obtained and transformed into haploid and diploid lab yeast strains. In the pdc2Δ344 mutants the DNA-binding and transactivation site of the protein remain intact, whereas in pdc2Δ519 only the DNA-binding site is conserved...
December 2017: AMB Express
https://www.readbyqxmd.com/read/28319775/dilute-alkali-pretreatment-of-softwood-pine-a-biorefinery-approach
#2
Ali Safari, Keikhosro Karimi, Marzieh Shafiei
Dilute alkali pretreatment was performed on softwood pine to maximize ethanol and biogas production via a biorefinery approach. Alkali pretreatments were performed with 0-2% w/v NaOH at 100-180°C for 1-5h. The liquid fraction of the pretreated substrates was subjected to anaerobic digestion. The solid fraction of the pretreatment was used for separate enzymatic hydrolysis and fermentation. High ethanol yields of 76.9‒78.0% were achieved by pretreatment with 2% (w/v) NaOH at 180°C. The highest biogas yield of 244mL/g volatile solid (at 25°C, 1bar) was achieved by the pretreatment with 1% (w/v) NaOH at 180°C...
March 7, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28319742/biochar-provides-a-safe-and-value-added-solution-for-hyperaccumulating-plant-disposal-a-case-study-of-phytolacca-acinosa-roxb-phytolaccaceae
#3
Shengsen Wang, Bin Gao, Yuncong Li, Yong Sik Ok, Chaofeng Shen, Shengguo Xue
In this work, an innovative approach using biochar technology for hyperaccumulator disposal was developed and evaluated. The heavy metal enriched P. acinosa biomass (PBM) was pyrolyzed to produce biochar (PBC). Both PBM and PBC were characterized with X-ray diffraction (XRD) for crystal phases, scanning electron microscopy (SEM) for surface topography, and analyzed for elemental composition and mobility. The results revealed that whewellite, a dominant crystal form in biomass, was decomposed to calcite after pyrolysis...
February 27, 2017: Chemosphere
https://www.readbyqxmd.com/read/28319702/volatile-organic-compounds-voc-formaldehyde-and-nitrogen-dioxide-no2-in-schools-in-johor-bahru-malaysia-associations-with-rhinitis-ocular-throat-and-dermal-symptoms-headache-and-fatigue
#4
Dan Norbäck, Jamal Hisham Hashim, Zailina Hashim, Faridah Ali
This paper studied associations between volatile organic compounds (VOC), formaldehyde, nitrogen dioxide (NO2) and carbon dioxide (CO2) in schools in Malaysia and rhinitis, ocular, nasal and dermal symptoms, headache and fatigue among students. Pupils from eight randomly selected junior high schools in Johor Bahru, Malaysia (N=462), participated (96%). VOC, formaldehyde and NO2 were measured by diffusion sampling (one week) and VOC also by pumped air sampling during class. Associations were calculated by multi-level logistic regression adjusting for personal factors, the home environment and microbial compounds in the school dust...
March 15, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28319363/real-time-observation-of-the-electrode-size-dependent-evolution-dynamics-of-the-conducting-filaments-in-a-sio2-layer
#5
Fang Yuan, Zhi Zhang, Chunru Liu, Feichi Zhou, Hei Man Yau, Wei Lu, Xiaoyan Qiu, H-S Philip Wong, Jiyan Dai, Yang Chai
Conducting Bridge Random Access Memory (CBRAM) is one of the most promising candidates for future non-volatile memories. It is important to understand the scalability and retention of CBRAM cells to realize better memory performance. Here we directly observe the switching dynamics of Cu tip/SiO2/W cells with various active electrode sizes using in-situ transmission electron microscopy. Conducting filaments (CFs) grow from the active electrode (Cu tip) to inert electrode (W) during the SET operations. The size of the Cu tip affects the electric-field distribution, the amount of the cation injection into electrolyte, and the dimension of the CF...
March 20, 2017: ACS Nano
https://www.readbyqxmd.com/read/28319129/changes-in-salivary-microbiota-increase-volatile-sulfur-compounds-production-in-healthy-male-subjects-with-academic-related-chronic-stress
#6
Bruno Dias Nani, Patricia Oliveira de Lima, Fernanda Klein Marcondes, Francisco Carlos Groppo, Gustavo Sattolo Rolim, Antonio Bento Alves de Moraes, Karina Cogo-Müller, Michelle Franz-Montan
OBJECTIVE: To investigate the associations among salivary bacteria, oral emanations of volatile sulfur compounds, and academic-related chronic stress in healthy male subjects. MATERIALS AND METHODS: Seventy-eight healthy male undergraduate dental students were classified as stressed or not by evaluation of burnout, a syndrome attributed to academic-related chronic stress. This evaluation was carried out using the Maslach Burnout Inventory-Student Survey questionnaire...
2017: PloS One
https://www.readbyqxmd.com/read/28318790/wood-burning-pollution-in-southern-chile-pm2-5-source-apportionment-using-cmb-and-molecular-markers
#7
Ana M Villalobos, Francisco Barraza, Héctor Jorquera, James J Schauer
Temuco is a mid-size city representative of severe wood smoke pollution in southern Chile; i.e., ambient 24-h PM2.5 concentrations have exceeded 150 μg/m(3) in the winter season and the top concentration reached 372 μg/m(3) in 2010. Annual mean concentrations have decreased but are still above 30 μg/m(3). For the very first time, a molecular marker source apportionment of ambient organic carbon (OC) and PM2.5 was conducted in Temuco. Primary resolved sources for PM2.5 were wood smoke (37.5%), coal combustion (4...
March 16, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28318240/ppm-detection-of-alcohol-vapors-via-metal-organic-framework-functionalized-surface-plasmon-resonance-sensors
#8
Wouter Vandezande, Kris P F Janssen, Filip Delport, Rob Ameloot, Dirk E De Vos, Jeroen Lammertyn, Maarten B J Roeffaers
The development of novel molecular sieves opens opportunities in the development of more sensitive analytical devices. In this paper, metal organic frameworks (MOFs), specifically ZIF-8 and ZIF-93, are grown on fiber optic based surface plasmon resonance (FO-SPR) sensors. FO-SPR has enabled sensitive sensing capabilities in biomedical settings and the addition of a MOF coating opens the way for the sensing of volatile organic compounds (VOCs) in gaseous media. FO-SPR probes were homogeneously functionalized with ZIF-8 and ZIF-93 in each case using two different precursor solutions to obtain a sequential nucleation and growth phase...
March 20, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28317778/physicochemical-and-sensory-aroma-and-colour-characterisation-of-a-non-centrifugal-cane-sugar-panela-beverage
#9
Juliana María García, Paulo César Narváez, Francisco José Heredia, Álvaro Orjuela, Coralia Osorio
Non-centrifugal cane sugar (NCS), also called "panela", is a high carbohydrate-content food obtained by boil evaporation of the sugar cane juice. This study was undertaken to assess physicochemical properties and sensory characteristics of panela beverage at two different concentrations. Evaluation of pH, °Brix, and colour (tristimulus colorimetry) was carried out in all panela drink samples. In order to characterise the odour-active volatiles of the beverage, a simultaneous steam distillation-solvent extraction method was applied using a mixture of diethyl ether-pentane (1:1,w/w) as solvent...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28317768/effect-of-xanthan-gum-on-the-release-of-strawberry-flavor-in-formulated-soy-beverage
#10
Jiao Xu, Zhiyong He, Maomao Zeng, Bingbing Li, Fang Qin, Linxiang Wang, Shengfang Wu, Jie Chen
The effects of xanthan gum on the release of strawberry flavor compounds in formulated soy protein isolate (SPI) beverage were investigated by headspace gas chromatography (GC). Seven strawberry flavor compounds (limonene, ethyl hexanoate, (Z)-3-hexenyl acetate, ethyl 2-methylbutanoate, ethyl butanoate, (Z)-3-hexen-1-ol and diacetyl) could be detected by GC and hence analyzed the gas-matrix partition coefficients (K). The release of flavor compounds was restrained in SPI and/or xanthan gum solution. The retention of (Z)-3-hexen-1-ol, limonene and diacetyl significantly changed (p<0...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28317762/evaluation-of-aroma-enhancement-for-ecolly-dry-white-wines-by-mixed-inoculation-of-selected-rhodotorula-mucilaginosa-and-saccharomyces-cerevisiae
#11
Xing-Chen Wang, Ai-Hua Li, Marta Dizy, Niamat Ullah, Wei-Xuan Sun, Yong-Sheng Tao
To improve the aroma profile of Ecolly dry white wine, the simultaneous and sequential inoculations of selected Rhodotorula mucilaginosa and Saccharomyces cerevisiae were performed in wine making of this work. The two yeasts were mixed in various ratios for making the mixed inoculum. The amount of volatiles and aroma characteristics were determined the following year. Mixed fermentation improved both the varietal and fermentative aroma compound composition, especially that of (Z)-3-hexene-1-ol, nerol oxide, certain acetates and ethyls group compounds...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28317734/aroma-compound-diacetyl-suppresses-glucagon-like-peptide-1-production-and-secretion-in-stc-1-cells
#12
Triona McCarthy, Christine Bruen, Fiona O'Halloran, Harriet Schellekens, Kieran Kilcawley, John F Cryan, Linda Giblin
Diacetyl is a volatile flavour compound that has a characteristic buttery aroma and is widely used in the flavour industry. The aroma of a food plays an important role in food palatability and thus intake. This study investigates the effect of diacetyl on the satiety hormone, glucagon-like peptide (GLP-1), using the enteroendocrine cell line, STC-1. Diacetyl decreased proglucagon mRNA and total GLP-1 from glucose stimulated STC-1 cells. This dampening effect on GLP-1 appears to be mediated by increasing intracellular cAMP levels, increasing synthesis of the G protein coupled receptor, GPR120, and its recruitment to the cell surface...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28317715/evaluation-of-penicillium-expansum-for-growth-patulin-accumulation-nonvolatile-compounds-and-volatile-profile-in-kiwi-juices-of-different-cultivars
#13
Yuan Wang, Tingting Shan, Yahong Yuan, Zhiwei Zhang, Chunfeng Guo, Tianli Yue
Patulin (PAT) contamination and changes of nonvolatile and volatile compounds caused by Penicillium expansum in fresh juices of 8 kiwi cultivars were investigated. Growth and PAT production of P. expansum were greater at 25°C than at 4°C. P. expansum grew in kiwi juices under pH ranging from 2.75 to 3.27 and produced 45.10-268.88μg/mL of PAT at 25°C. Decreases occurred in malic acid and soluble protein; while consumption and production simultaneously happened for reducing sugar, total soluble solid, titratable acid, citric acid, ascorbic acid and total phenolics...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28317706/impact-of-processing-on-odour-active-compounds-of-a-mixed-tomato-onion-puree
#14
Maria Koutidou, Tara Grauwet, Ann Van Loey, Parag Acharya
Gas chromatography-olfactometry revealed thirty-two odour-active compounds in a heat-processed tomato-onion puree, among which twenty-seven were identified by gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOF MS). Based on the results of two olfactometric methods, i.e. detection frequency and aroma extract dilution analysis, the most potent aroma components include: dipropyl disulfide, S-propyl thioacetate, dimethyl trisulfide, 1-octen-3-one, methional, dipropyl trisulfide, 4,5-dimethylthiazole, 2-phenylacetaldehyde and sotolone...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28317704/free-and-glycosidically-bound-volatile-compounds-in-sun-dried-raisins-made-from-different-fragrance-intensities-grape-varieties-using-a-validated-hs-spme-with-gc-ms-method
#15
Dong Wang, Chang-Qing Duan, Ying Shi, Bao-Qing Zhu, Hafiz Umer Javed, Jun Wang
The conditions of sample pretreatments and HS-SPME for extracting volatile compounds from raisins were optimized, and the method was validated in the study. Free and glycosidically bound volatile compounds in three different fragrance intensities raisins were analysed using this method. There were 91 compounds identified, and 72, 26 and 8 of these compounds came from fresh grapes, the auto-oxidation of unsaturated fatty acids (UFAO) and the Maillard reaction, respectively. The aroma profiles of Thompson Seedless raisins (TSRs) and Centennial Seedless raisins (CSRs) were similar, while the floral, fruity, green and roasted aromas of CSRs were higher than those of TSRs due to the contributions of benzeneacetaldehyde, 2-pentylfuran, (E)-2-nonenal and 3-ethyl-2,5-dimethyl pyrazine...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28317451/inclusion-of-saccharina-latissima-in-conventional-anaerobic-digestion-systems
#16
F Ometto, A Berg, A Björn, L Safaric, B H Svensson, A Karlsson, J Ejlertsson
Loading macroalgae into existing anaerobic digestion (AD) plants allows us to overcome challenges such as low digestion efficiencies, trace elements limitation, excessive salinity levels and accumulation of volatile fatty acids (VFAs), observed while digesting algae as a single substrate. In this work, the co-digestion of the brown macroalgae Saccharina latissima with mixed municipal wastewater sludge (WWS) was investigated in mesophilic and thermophilic conditions. The hydraulic retention time (HRT) and the organic loading rate (OLR) were fixed at 19 days and 2...
March 18, 2017: Environmental Technology
https://www.readbyqxmd.com/read/28317332/high-throughput-gas-chromatography-for-volatile-compounds-analysis-by-fast-temperature-programming-and-adsorption-chromatography
#17
Ronda Gras, Yujuan Hua, Jim Luong
The synergy of combining fast temperature programming capability and adsorption chromatography using fused silica based porous layer open tubular columns to achieve high throughput chromatography for the separation of volatile compounds is presented.A gas chromatograph with built-in fast temperature programming capability and having a fast cool down rate was used as a platform. When these performance features were combined with the high degree of selectivity and strong retention characteristic of porous layer open tubular column technology, volatile compounds such as light hydrocarbons of up to C7 , primary alcohols, and mercaptans can be well separated and analyzed in a matter of minutes...
March 20, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28315955/symbiosis-with-systemic-fungal-endophytes-promotes-host-escape-from-vector-borne-disease
#18
L I Perez, P E Gundel, H J Marrero, A González Arzac, M Omacini
Plants interact with a myriad of microorganisms that modulate their interactions within the community. A well-described example is the symbiosis between grasses and Epichloë fungal endophytes that protects host plants from herbivores. It is suggested that these symbionts could play a protective role for plants against pathogens through the regulation of their growth and development and/or the induction of host defences. However, other endophyte-mediated ecological mechanisms involved in disease avoidance have been scarcely explored...
March 18, 2017: Oecologia
https://www.readbyqxmd.com/read/28315236/detection-of-ketones-by-a-novel-technology-dipolar-proton-transfer-reaction-mass-spectrometry-dp-ptr-ms
#19
Yue Pan, Qiangling Zhang, Wenzhao Zhou, Xue Zou, Hongmei Wang, Chaoqun Huang, Chengyin Shen, Yannan Chu
Proton transfer reaction mass spectrometry (PTR-MS) has played an important role in the field of real-time monitoring of trace volatile organic compounds (VOCs) due to its advantages such as low limit of detection (LOD) and fast time response. Recently, a new technology of proton extraction reaction mass spectrometry (PER-MS) with negative ions OH(-) as the reagent ions has also been presented, which can be applied to the detection of VOCs and even inorganic compounds. In this work, we combined the functions of PTR-MS and PER-MS in one instrument, thereby developing a novel technology called dipolar proton transfer reaction mass spectrometry (DP-PTR-MS)...
March 17, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28315117/the-evolution-of-pollution-profile-and-health-risk-assessment-for-three-groups-svocs-pollutants-along-with-beijiang-river-china
#20
Jiao Tang, Taicheng An, Jukun Xiong, Guiying Li
Three important groups of semi-volatile organic compounds (SVOCs), polycyclic aromatic hydrocarbons (PAHs), organic chlorinated pesticides (OCPs) and phthalate esters (PAEs), were produced by various human activities and entered the water body. In this study, the pollution profiles of three species including 16 PAHs, 20 OCPs and 15 PAEs in water along the Beijiang River, China were investigated. The concentrations of Σ16PAHs in the dissolved and particulate phases were obtained as 69-1.5 × 10(2) ng L(-1) and 2...
March 17, 2017: Environmental Geochemistry and Health
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